adapt celery to honcho setup

.env.example

@@ -10,6 +10,7 @@ DATABASE_URL=sqlite:///db.sqlite3
 
 REDIS_PORT=7963
 CACHE_URL=redis://127.0.0.1:${REDIS_PORT}/0
+TASK_BROKER_URL=redis://127.0.0.1:${REDIS_PORT}/1
 
 # Used to select which other services to run alongside
 # manage.py, pytest and runserver